a) Field of the Invention
The invention is directed to a loading and unloading station for semiconductor processing installations with at least one closeable charging opening through which wafer-shaped or disk-shaped objects which are accommodated in a transporting container can be loaded, unloaded and reloaded after removing a closure, wherein the transporting container is provided with a container cover which extends substantially at right angles to the loading plane.
b) Description of the Related Art
For the purpose of charging semiconductor processing installations, it is known to use so-called SMIF boxes as magazine containers with a relatively small enclosed volume in which wafer magazines can be stored and transported. The box can be placed on an opening mechanism in an enclosure or housing which encloses one or more work stations so as to keep them free of dust. The box and opening mechanism have closing elements which are adapted to one another and which can be opened simultaneously one above the other so that dust particles resting on the outside of the closing elements can be enclosed therebetween when the wafer magazines are lowered into the housing together with the two closing elements. The box itself encloses the opening formed in the housing.
A loading and unloading device according to the German Patent 43 26 309 C1, for example, or a device having another operating sequence serves to remove the magazines from the transporting containers and place them in the processing installation. After the semiconductor wafers are processed, the magazines are transported back in the transporting containers.
The technique of SMIF boxes is especially suited for semiconductor wafers with smaller diameters, as is conventional. In view of the material characteristics of the semiconductor wafers, these SMIF boxes and the wafer magazines used with them are becoming increasingly unsuitable as transporting containers as the diameter of semiconductor wafers increases. Transporting containers which take over the function of magazines at the same time are already known for semiconductor wafers of this type. Loading, unloading and reloading of the semiconductor wafers is effected individually in a plane parallel to the surface of the semiconductor wafers, wherein the transporting container can be closed by a container cover extending substantially at right angles to the loading and unloading plane. Accordingly, in contrast to the SMIF box, the container cover is removed and inserted laterally rather than in a downward direction.
Since the transporting containers are enclosed by a space with low requirements as regards cleanness and since there are no magazines which can be loaded and unloaded such as those used in the SMIF technique, the charging of semiconductor processing installations proceeding from these transporting containers and the transporting back from such installations into the transporting containers presents problems. Moreover, the problem is exacerbated in that optional loading and unloading into and out of a greater number of transporting containers must be ensured under certain circumstances and the containers themselves must be supplied and removed by operating personnel under favorably ergonomic conditions.
An arrangement for storing, transporting and inserting substrates is known from EP 542 793 B 1. In this arrangement, a cassette with a lateral closing cap is arranged opposite a loading slot. The cassettes are brought into the loading position one after the other by a lifting plate which can hold a packet of stacked cassettes. When this position is reached, the closing cap is swiveled open at one edge and the substrate wafer is inserted into the clean room by a drawer which can travel out of the cassette. An air flow exiting from the loading slot prevents particles from penetrating into the clean room in that it passes through an open gap between a protruding seal and the cassette.